Vestibulocochlear or VIII cranial nerve The Vestibulocochlear nerve has two components, with the cochlear provides innervation to the hearing apparatus while the vestibular branch is concerned with balance. Conduction deafness results from interference with the transmission of sound waves in the external canal or middle ear to the organ of Corti. In sensorineural hearing loss, the lesion can be in the inner ear, the vestibulocochlear nerve or the brain. Because of the extensive bilateral connections of the ear, unilateral sensorineural hearing loss is usually due to lesion of the nerve nucleus or the nerve itself. Bilateral hearing loss can be either due to a central lesion or bilateral exposure to toxins and infectious agents. • Auditory Component - Look o See if the child is wearing a hearing aid and remove it, while testing for hearing impairment. o Examine the pinna and look for scars behind the ears. o Do an otoscopic examination of both ears. Look for wax or other obstruction in the external auditory meatus and perforation of the tympanic membrane. - Whisper test The Whisper Test is a screening test for hearing loss in older children and correlates with a hearing loss of 30 decibels. o Stand about two feet behind the child on one side so that they cannot read your lips. o Place your finger on the external auditory meatus of the ear which is not being tested to mask the sound. o At the end of your exhalation, whisper a word with two distinct syllables towards the ear which is being tested. o Ask the child to repeat the two syllable word. o Repeat the test on the other side - Distraction test It is a behavioural screening test of hearing for babies between six and eighteen months. The test capitalises on ... ... middle of paper ... ...ormally, the child should be able to turn the head against resistance. Hypoglossal or XII cranial nerve The Hypoglossal nerve provides motor supply to the intrinsic muscles of the tongue. • Look - Ask the child to open the mouth and inspect the tongue on the floor of the mouth. Observe the tongue for signs of wasting or fasciculations. - Next, ask the child to protrude their tongue 'Stick out your tongue'. Look for deviation of the tongue from midline. In peripheral hypoglossal lesion, there will be atrophy and fasciculations and the tongue will deviate towards the side of the lesion. In central lesion, there is spastic paralysis of the tongue without atrophy or muscle fibrillation and paralysis and the tongue deviates to the opposite side. • Motor Component - Ask the child to push the tongue into each cheek while you press from outside with your finger.